New in Breevy 3.09, released today, is the ability to disable individual folders (previously, you could only enable or disable all folders -- by changing Breevy's status to Disabled in the main window or with the toggle status hotkey.)
Disabling folders is super easy: just right-click the folder(s) you'd like to disable and select Disable.
Abbreviations inside of the folders you have disabled won't be expanded when you type them. Also, disabled folders have a gray folder icon next to them instead of a yellow one:

To re-enable a disabled folder, right-click it and select Enable.
As usual, you can download the new version from Breevy's main page. Enjoy. 